Bulletin No.: PIP5486C
Published date: 03/13/2018

Preliminary Information
PIP5486C Ticking, Tap, or Rattle Noise From Engine With Possible Misfire DTCs.
Models
Brand:

Model:

Model Years:

VIN:
from

Engine:

to

Transmissions:

Buick

LaCrosse

2017 - 2018

ALL

ALL

3.6 LGX

ALL

Cadillac

ATS

2016 - 2018

ALL

ALL

3.6 LGX

ALL

Cadillac

CT6

2016 - 2018

ALL

ALL

3.0 LGW, 3.6 LGX

ALL

Cadillac

CTS

2016 - 2018

ALL

ALL

3.6 LGX

ALL

Cadillac

XT5

2017 - 2018

ALL

ALL

3.6 LGX

ALL

Chevrolet

Camaro

2016 - 2018

ALL

ALL

3.6 LGX

ALL

Chevrolet

Colorado

2017 - 2018

ALL

ALL

3.6 LGZ

ALL

GMC

Acadia

2017 - 2018

ALL

ALL

3.6 LGX

ALL

GMC

Canyon

2017 - 2018

ALL

ALL

3.6 LGZ

ALL

Supersession Statement
PIP5486C adds picture and direction to inspect non-AFM rocker shla holding clips. Please discard PIP5486B
Involved Region or Country North America
Additional Options (RPO)

N/A
Customers may bring their vehicle into the dealership for a rattle, tick, or knock type noise. This noise
may also be accompanied by DTC P0300, P0302 or P0305 on the Active Fuel management System (AFM)
cylinders.
Note: If there are any drivability concerns they should be addressed prior to the following
diagnostic progression including any misfire DTC.
Note: Please take a sound file or video with sound of the noise prior to disassembly.

Condition

This may be needed when contacting TAC or to be sent to engineering.
This could be all the time, only under load, or intermittent depending on the severity of the
noise.
You may find this noise hard to isolate to one area in the engine.
After you have recorded a sound file of the noise try to isolate the noise to a general area of the
engine.
At that point following the steps in this PI in ORDER may help pinpoint the concern.
This condition may be caused by spongy stationary hydraulic lash adjusters (SHLAs) (lifters) or a

Cause

damaged switching roller finger followers (SRFF). The condition could be all the time, only under load,
or intermittent depending on the cause.

Correction:
1) Perform injector diagnosis to ensure there are no leaking injectors causing a noise due to excessive fuel in 1 cylinder
a) Perform GDS2 or AFIT test on injectors to isolate a leaking injector.
b) Replace any out of specification injectors
c) Reevaluate the noise.

2) Perform cylinder cancellation for each cylinder this may help pinpoint the source of a rattle noise.
3) Remove the intake manifold and visually inspect for excessive carbon on the intake valve stems and top of the valve causing noise.
a) If carbon is present then follow the latest version of 16-NA-383 to clean the valves or replace heads as needed.
b) Reevaluate the noise concern.
4) Remove the cam cover of the affected bank or both if needed to inspect for soft , spongy or damaged SHLAs or rockers on all
cylinders.
a) Push down on the rocker end at the SHLA to test for soft or spongy feel. (See below)

b) Check for any visible damage to non-AFM rocker clips and replace as needed. (See Below)

c) If soft , spongy, or damaged SHLAs or rockers are found on either the intake or exhaust side of any cylinder it will be necessary to
replace all the affected cylinder SHLAs or rockers and retest.
NOTE: If all shla's (lifters) are hard and no damage to rockers is visible proceed to step 5
a) If the replacement SHLAs are still spongy it will be necessary to remove the affected head and inspect the head gasket for debris in
the oil passages noted below.

b) If debris is found, inspect the camshaft caps for wear or discoloration due to lack of oil.
c) If wear or discoloration is found then replace the cylinder head assembly with camshafts.
d) If there is no wear or discoloration, clean the oil passages and replace the head gasket.
e) Change the oil and filter
f) Reevaluate the noise concern.
5) Without starting engine, crank engine over and ensure that the valves are opening and closing.
If they are not operating correctly it will be necessary to inspect the (SRFF) for any damage.

6) Inspect the SRFF' and rocker assemblies for any damage or dislodge.
Camshaft carrier assembly removal will be necessary to fully inspect the rockers and SRFF's.
Below are pictures of possible SRFF failures.
If any one of the SRFF’s are damaged it will be necessary to replace all four on the affected cylinder.

For the above conditions engine replacement is not necessary.
Please perform the repairs for these conditions.
7) If noise condition is still present proceed to step 8.
8) Raise the vehicle while running or with an assistant inside.
a) With chassis ears or a stethoscope, listen to the right and left side of the engine
b) Once the noise is isolated or if unable to isolate, remove the piston and rod assemblies from the affected bank(s) to inspect for
either; a loose rod bushing in the rod, or a loose wrist pin in the bushing. We have seen both.
c) There should be no metal through the oil for this condition.
d) If this is found a piston and rod assembly will repair this noise.
Once all of the above inspections and / or diagnostics are completed, if nothing is found to be the cause for the noise, engine
replacement MAY be necessary.
NOTE: This PI will be updated or changed to a TSB as more information and updated parts become available.

Warranty Information
For Vehicles Repaired Under Warranty Use Appropriate Labor Operation For Process Performed.

Version History
Version

4

Modified

12/01/2017 - Updated to add Model year
2/12/2018 updated to reference 16-NA-383
3/12/2018 to request inspection of non-afm rockers.

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